Copper(II) Complex with the Tridentate Ligand N, N-bis(2-ethyl-4-methyl-imidazol-5-ylmethyl)phenylethylamine (biaq). X-ray Crystal Structure and Biological Activity on Bacillus subtilis of [Cu(biaq)Cl2].

The ligand N, N-bis(2-ethyl-4-methyl-imidazol-5-ylmethyl)-1-phenylethylamine (biaq) was prepared by Mannich reaction of 2-ethyl-4-methyl-1 H-imidazole, ( R)-1-phenylethylamine and formaldehyde. It was characterized by FTIR and NMR spectroscopy. This ligand reacts with CuCl₂ to give a coordination compound with formula [Cu(biaq)Cl₂]. In this compound, biaq acts as a tridentate ligand with one tertiary amine and two azole nitrogen atoms coordinated to the central metal atom. The complex was characterized by FTIR spectroscopy, elemental analysis, and X-ray diffraction. The X-ray structure of [Cu(biaq)Cl₂] shows a pentacoordinate cooper(II) atom, where two chloride ions and the three nitrogen atoms of the biaq ligand are coordinated in a distorted square pyramidal arrangement. The biological activity of the complex [Cu(biaq)Cl₂] was tested using the Gram positive bacterium Bacillus subtilis as a model. Results revealed that the copper complex interfered with bacterial growth, inducing cell death, most probably by altering the primary structure of the chromosome, since a significant increase of the mutation frequency to rifampicin resistance was observed. [ABSTRACT FROM AUTHOR]